L精氨酸在大鼠原位肝移植冷缺血再灌注损伤中的作用

目的探讨Ｌ精氨酸在大鼠原位肝移植冷缺血再灌注损伤过程中对移植肝及肺的功能作用．方法应用同基因Ｗｉｓｔａｒ大鼠原位肝移植（ＯＬＴ）动物模型，６６只大鼠随机分成３组（ｎ＝１１）：Ｌ精氨酸组（ＬＡ）、ＮＯＳ抑制剂组（ＬＮＡＭＥ，ＬＮ）及乳酸钠林格液组（ＬＲ），供肝保存６ｈ再行原位肝移植术．结果大鼠原位肝移植缺血再灌注后血清ＮＯｘ水平及肝组织ｃＧＭＰ水平迅速下降．应用Ｌ精氨酸以加强一氧化氮生物合成途径（ＮＯＳＰ），能显著延长受体的存活率，ＬＲ组受体１ｗｋ存活率为２０％，ＬＡ组为８０％（ｎ＝６，Ｐ＜００１ｖｓＬＲ），并能明显改善肝功能；病理检查示Ｌ精氨酸能维持肝细胞完整性，促进肝再生，而且对再灌注时合并肺损伤也有明显的保护作用．ＮＯＳ抑制剂则能降低术后受体的存活率，加剧肝功能恶化；病理检查示肝内血栓形成，移植肝及肺组织结构严重破坏及更为严重的炎症反应．结论在大鼠原位肝移植缺血再灌注损伤过程中，Ｌ精氨酸器官保存液加强ＮＯ途径（ＮＯＳＰ）将对移植肝及肺具有重要的保护作用．表明ＮＯ合成途径很可能是肝移植器官保存成功的关键因素，从而为加强肝移植器官保存提供了一种新的药理学途径．     

苦参碱对大鼠原位肝移植冷缺血再灌注损伤的保护作用

目的:探讨苦参碱对大鼠原位肝移植中供肝冷缺血再灌注损伤的保护作用及其机制方法:应用延长保存的大鼠原位肝移植模型, 大鼠224只随机分为对照组、低剂量(40 mg／ kg)、高剂量苦参碱治疗组(80 mg／kg)和假手术组,将供肝在4℃林格液中保存5 h后植入受体,分别观察移植术后1 wk生存率,并且检测移植术后1,2,4,24 h血ALL TNF-α,内毒素 (ET),透明质酸(HA),一氧化氮(NO)及肝组织丙二醛(MDA),超氧化物歧化酶(SOD),细胞间黏附分子-1(ICAM-1)的含量,并观察移植肝脏病理形态学的改变．结果:与对照组比较,苦参碱低剂量、高剂量治疗组术后1 wk生存率显著增加(75％,75％ vs 0,P<0．01),肝功能改善,血清HA(277．62 ±29．06,406．84±95．04 μg／L vs 1109．42± 110．28 μg／L,P<0．01)和肝组织ICAM-1表达均显著减少,血清NO含量增加(53．1±5．1,54．2 ±4．9 μmol/L vs 30．2±2.3 μmol／L,P<0．01), TNF-α(1．69±0．22,1．29±0．33 U／L vs 5．96 ±0．59 U／L,P<0．01)、ET(0．343±0．111, 0_302±0．059 kEU／L vs 0．643±0．110 kEU／L． P<0．01)以及肝组织MDA(0．87±0．41,0．69± 0．22 μmol／g vs 2．35±0．54 μmol／g,P<0．01) 水平均明显降低,肝组织SOD(19．89±1．84, 21．04±1．86 kU／g vs 13．39±0．85 kU／g,P<0．01) 水平均明显升高,肝细胞和肝窦内皮细胞形态也发生改善．结论:苦参碱可以通过减轻再灌注后内毒素血症,抑制库氏细胞激活及释放TNF-α, ICAM-1等炎症性细胞因子,清除氧自由基,促进NO合成等途径,减轻肝细胞及肝窦内皮细胞的损伤．     

心脏停搏供体大鼠供肝热缺血对原位肝移植物的影响

目的:探讨来自心脏停搏供体大鼠肝移植供肝热缺血再灌注损伤对移植物的影响.方法:实验分为4组:对照组(C)和移植组,移植组根据供肝获取前经历供体心脏停搏时间的不同分为3组:热缺血0 min(W0组)、热缺血15min(W15组)和热缺血30 min(W30组),其后用建立大鼠动脉化原位肝移植模型,每组均为24只大鼠,分别测定术后3、7、14和30 d移植肝组织学、肝功能和细胞增殖核抗原Ki-67蛋白的变化,每个时间点各取6只大鼠处死.结果:随着供肝热缺血时间的延长,移植肝损伤加重,并且恢复过程也延长.移植组和对照组术后第3、7、14和30天血清ALT、AST均无显著性改变.肝移植术后早期肝细胞Ki-67表达水平随供肝热缺血时间的延长而增高,术后14 d恢复正常.各组的肝细胞Ki-67表达均与血清ALT、AST无关.结论:肝移植过程中供肝热缺血主要损伤肝细胞,并随着供肝热缺血时间的延长移植肝细胞损伤加重,肝细胞功能恢复早于其形态学恢复.     

Intention-to-treat analysis of liver transplantation for hepatocellular carcinoma: living versus deceased donor transplantation

Vitamin D supplementation was reported to improve the probability of achieving a sustained virological response when combined with antiviral treatment against hepatitis C virus (HCV). Our aim was to determine the in vitro potential of vitamin D to inhibit HCV infectious virus production and explore the mechanism(s) of inhibition. Here we show that vitamin D(3) remarkably inhibits HCV production in Huh7.5 hepatoma cells. These cells express CYP27B1, the gene encoding for the enzyme responsible for the synthesis of the vitamin D hormonally active metabolite, calcitriol. Treatment with vitamin D(3) resulted in calcitriol production and induction of calcitriol target gene CYP24A1, indicating that these cells contain the full machinery for vitamin D metabolism and activity. Notably, treatment with calcitriol resulted in HCV inhibition. Collectively, these findings suggest that vitamin D(3) has an antiviral activity which is mediated by its active metabolite. This antiviral activity involves the induction of the interferon signaling pathway, resulting in expression of interferon-β and the interferon-stimulated gene, MxA. Intriguingly, HCV infection increased calcitriol production by inhibiting CYP24A1 induction, the enzyme responsible for the first step in calcitriol catabolism. Importantly, the combination of vitamin D(3) or calcitriol and interferon-α synergistically inhibited viral production. CONCLUSION: This study demonstrates for the first time a direct antiviral effect of vitamin D in an in vitro infectious virus production system. It proposes an interplay between the hepatic vitamin D endocrine system and HCV, suggesting that vitamin D has a role as a natural antiviral mediator. Importantly, our study implies that vitamin D might have an interferon-sparing effect, thus improving antiviral treatment of HCV-infected patients.     

活性氧簇在肝脏移植缺血再灌注中的作用

肝移植缺血再灌注是一个复杂的、多因子参与的病理生理过程,包括活性氧、细胞因子、枯否细胞和中性粒细胞的激活．氧化应激是许多肝病的主要发病机制,在肝脏移植中是缺血再灌注引起肝损伤的主要原因．氧分子和活性氧簇(reactive oxygen species,ROS)的化学、生理功能,以及促氧化物和抗氧化物之间的平衡对正常的线粒体和细胞功能是至关重要的． ROS的主要来源是肝脏中的线粒体和细胞色素P450酶,以及库氏细胞和中性粒细胞,其在缺血再灌注和缺血预处理过程中对损伤的决定性作用存在争议．     

Acute promyelocytic leukemia after living donor partial orthotopic liver transplantation

We encountered a 12-year-old girl with acute promyelocytic leukemia (APL) that occurred 21 months after a living donor partial orthotopic liver transplantation from her father for ornithine transcarbamylase deficiency. FK-506 had been administered for prophylaxis against graft-versus-host reaction. The bone marrow specimen revealed a massive infiltration of promyelocytic blasts (M3 by FAB classification) with chromosome 46, XX, t (15; 17) (q22; q12), being the recipient origin. A PML/RAR alpha chimeric gene was detected by RT-PCR. The patient was diagnosed as having APL and successfully induced to complete remission by chemotherapy including daunorubicin (DNR), cytarabine (araC), and all-trans retinoic acid (ATRA). She has been in continuous remission for 12 months after the treatment. Leukemia after liver transplantation is generally taken as a rare complication. However, recent advances in the survival rate of patients who have undergone liver transplantation will lead to an increase of such cases.     

Gender of donor influences outcome after orthotopic liver transplantation in adults

Because male and female livers not only differ with respect to estrogen and androgen receptor content, but also demonstrate sexual dimorphism of certain functions, we examined the effect of donor gender on graft survival following liver transplantation (OLTx) in adults. Between February 1981 and February 1988, 982 OLTx procedures were performed in 789 adult patients at the University of Pittsburgh. In this study, OLTx was categorized as a failure if the patient died or required retransplantation within 60 days of the surgery. When the donor-recipient gender combinations were male-male, male-female, and female-female, the failure rates were 28%, 28%, and 36%, respectively. In contrast, 60% of female donor livers failed in male recipients. Compared to the pooled donor-recipient gender combinations, the odds of failure for female-male liver grafts were increased 3.7-fold (95% confidence interval: 6.5, 2.1;P<0.001). These findings may result, at least in part, from alterations in the sex hormone milieu or changes in the graft estrogen or androgen receptor content.     

Terlipressin versus placebo in living donor liver transplantation

<正>To the Editor:Terlipressin is a long-acting synthetic analogue of vasopressin,demonstrating several potential benefits in the context of living donor liver transplantation (LDLT).During the recipient hepatectomy,terlipressin reduces the portal flow.Consequently,it may mitigate the extent of bowel congestion following portal vein clamping.By decreasing portal hyperperfusion and hypertension,it protects the graft from further injury and improves renal blood flow.All the above described be...     

Transesophageal ultrasonography during orthotopic liver transplantation: Show me more

The first perioperative transesophageal echocardiography (TEE) guidelines published 21 years ago were mainly addressed to cardiac anesthesiologists. TEE has since expanded its role outside this setting and currently represents an invaluable tool to assess chamber sizes, ventricular hypertrophy, and systolic, diastolic, and valvular function in patients undergoing orthotopic liver transplantation (OLT). Right‐sided microemboli, right ventricular dysfunction, and patent foramen ovale (PFO) are the most common intra‐operative findings described during OLT. However, left ventricular outflow tract obstruction and left ventricular ballooning syndrome are more difficult to recognize and less frequent. Transesophageal ultrasonography (TEU) during OLT is also underused. Its applications are as follows: (1) assistance in the difficult placement of pulmonary arterial catheters; (2) help with catheterization of great vessels for external veno‐venous bypass placement; (3) intra‐operative evaluation of surgical liver anastomosis patency, if feasible, through the liver window; and (4) intra‐operative investigation of “acute hypoxemia” due to pulmonary and cardiac issues using trans‐esophageal lung ultrasound (TELU). The aims of this review are as follows: (1) to summarize the uses of TEE and TEU throughout all phases of OLT, and (2) to describe other new feasible applications.     

The effect of methylene blue during orthotopic liver transplantation on post reperfusion syndrome and postoperative graft function

Background/Purpose

In orthotopic liver transplantation (OLT), a major component of the post-reperfusion syndrome is hypotension, which may lead to additional graft liver ischemia-reperfusion injury. A proposed mechanism of reperfusion hypotension is the massive induction of oxidative stress triggering the release of pro-inflammatory mediators, including nitric oxide (NO). Methylene blue (MB) is an inhibitor of inducible NO synthase and an NO scavenger that has been shown to attenuate reperfusion hypotension. Of note, recent reports have shown that the exogenous administration of NO during OLT significantly improved the recovery of the graft liver. Therefore, we sought to investigate the effects of MB on the functional recovery of the graft liver following OLT.

Methods

We analyzed retrospective data from 715 patients who underwent OLT between 2003 and 2008. We classified patients into those who received a 1?C1.5?mg/kg intravenous bolus of MB immediately prior to reperfusion (MB group) and those who did not (control group). Propensity score matching was used to adjust for differences between patients who received intraoperative MB and those who did not, and these data were used to determine the association between a single MB bolus during OLT and postoperative graft dysfunction.

Results

Our study cohort consisted of 715 OLT patients, of whom 105 received MB and 610 did not. After propensity score matching, demographic and donor data were similar in the two groups, except for the older age of recipients in the MB group (55.5?±?0.9 vs 53.1?±?0.8 years, p?=?0.026). No differences were seen in mean arterial pressure changes after reperfusion and no differences were found in vasopressor requirements (bolus or infusion) or transfusion requirements. In addition, there was no significant difference in the incidence of primary nonfunction, retransplantation within 60?days, acute rejection, or graft survival between the groups by multivariate analysis or Kaplan?CMeier survival analysis.

Conclusions

In our study, the administration of MB at 1?C1.5?mg/kg immediately prior to reperfusion did not prevent post-reperfusion hypotension and did not decrease vasopressor usage or transfusion requirements after reperfusion. Also, MB did not have any impact on postoperative graft function. These findings may argue against the routine use of MB during OLT.     

Concomitant donor heart coronary artery bypass grafting during orthotopic heart transplantation

A 54-year-old diabetic woman with severe cardiomyopathy was placed on our heart transplant candidate list. The patient's condition rapidly worsened and a potential donor-a 45-year-old man whose blood was compatible with that of our patient-was located. Because of the donor's age, coronary arteriography was done, and stenosis in the midleft anterior descending coronary artery was identified. Since the patient's status was critical, the donor heart was accepted despite the presence of stenosis. We used the recipient's internal mammary artery to bypass the stenosis in the left anterior descending artery of the donor heart after performing a standard orthotopic heart transplant. The patient's postoperative course has been relatively free of complications, and the cardiac allograft has functioned well. The early results in this patient are comparable to those of our historical transplant control group. We suggest that the impact of donor organ shortages may be lessened by use of innovative procedures and extended donor selection criteria.     

Effects of ischemic postconditioning on reperfusion injury in rat liver grafts after orthotopic liver transplantation

Aim: The effects of ischemic postconditioning (IPostC) on ischemia reperfusion (IR) injury of liver grafts was examined in rats after orthotopic liver transplantation (OLT). Methods: Male Wistar rats were used as donors and recipients to establish a liver transplantation model. The animals were randomly divided into four groups: sham‐operated (SO, n = 6), IR (n = 6), IPostC1 (n = 6) and IPostC2 (n = 6). IPostC was achieved by several intermittent interruptions of blood flow in the early phase of reperfusion. Several parameters of hepatic damage, oxidative stress, neutrophil infiltration and the expression of TNF‐α and MIP‐2 were detected as well as microscopic examination. Nitric oxide release and liver NO synthases (endothelial NO synthase and inducible NO synthase) expression were also measured. Results: We observed that a significant reduction in alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase values in two IPostC groups when compared with IR group. The increases in hepatic malondialdehyde, and decreases in superoxide dismutase and reduced glutathione levels after orthotopic liver transplantation were significantly inhibited by IPostC. IR induced increase in hepatic myeloperoxidase content, TNF‐α and MIP‐2 expression were also lowered by IPostC. The increases in NO content and NOS protein expression were much more prominent in IPostC treated groups. Animals treated with IPostC presented minimal hemorrhage and reduced signs of liver injury. There was no significant difference between two IPostC treated groups. Conclusions: IPostC provided significant protection against IR injury to liver grafts. The protective effect of IPostC is closely related to the NO production following the increase in endothelial and inducible NO synthases expression and the suppression of tumor necrosis factor‐α and macrophage inflammatory protein‐2 overproduction.     

Advantages of venous bypass during orthotopic transplantation of the liver

Venous bypass restores normal hemodynamic physiology during the critical anhepatic phase of orthotopic transplantation of the liver. Its routine use in adults undergoing transplantation in Pittsburgh has resulted in lower operative blood losses, a lower frequency of postoperative renal failure, and a greater probability of survival for all but the highest risk patients. Because it allows for a longer anhepatic phase, the surgeon has the option of tailoring the native hepatectomy to the needs of the individual case, even to the point, in difficult cases, of obtaining most of the hemostasis after removal of the native liver, but before sewing in the donor organ. Selective use of bypass in children may offer similar advantages.     

Graft versus host disease after orthotopic liver transplantation documented by analysis of short tandem repeat polymorphisms

We report a case of graft versus host disease after liver transplantation in which the diagnosis was made by short tandem repeat analysis. A retrospective analysis using a bone marrow sample showed the presence of chimerism already at a time when the characteristic full clinical picture of graft versus host disease had not yet developed, opening the way for the early diagnosis and treatment.